Species Description: Catenazzi, A. and Ttito, A. 2016. A new species of Psychrophrynella (Amphibia, Anura, Craugastoridae) from the humid montane forests of Cusco, eastern slopes of the Peruvian Andes. PeerJ 4:e1807; DOI 10.7717/peerj.1807

DescriptionPsychrophrynella chirihampatu is a small sized member of the family Strabomantidae with snout-vent length ranges from 16.1 – 24.1 mm in males and from 23.3 – 27.7 mm in females. The head is slightly longer in length than in width and has a small snout, which may look short and rounded from the dorsal and lateral views. The lips are rounded. The laterally directed nostril is close to the snout and does not protrude. The canthus rostralis appears somewhat concave from the dorsal view and convex from the profile view. The loreal region is flat. The eye has a diameter that is slightly larger than the distance between the eye and the nostril. The upper eyelid is smooth and the interorbital region is flat with no cranial crests. The tympanic membrane is present but the tympanic annulus is barely visible and the supratympanic fold is weak. On each side of the head there are postrictal ridges. There are vocal sacs and slits in males. The body is characterized by having smooth dorsal skin with many small warts that are denser toward the posterior of the animal, mild dorsolateral folds on the upper body, no pectoral fold, and smooth skin on the ventrum and flanks. The cloaca does not have tubercles and does not protrude. The forearms do not have tubercles or folds. The palm has a flat, oval palmar tubercle, and an equally long, but wider thenar tubercle. There are no supernumerary palmar tubercles. Males do not have nuptial pads. The fingers have prominent, oval subarticular tubercles with the largest ones found at the base of the fingers. All the fingers lack lateral fringes, the tips of fingers are bulging and do not expand laterally, and the relative finger lengths are 3 > 4 > 2 > 1. The hindlimbs are relatively long, as is the foot. The upper and posterior surfaces of the hindlimbs are similar in texture to the dorsum. The inner edge of the tarsus has a characteristic elongated, oblique fold-like tubercle. The outer edge of the tarsus and the heel do not have tubercles. There is a large, high, oval inner metatarsal tubercle and a smaller conical, rounded outer metatarsal tubercle. There are also a few small, weakly defined supernumerary tubercles. The subarticular tubercles are rounded and oval in the ventral view. All the toes lack lateral fringes and webbing, the tips of toes are somewhat pointed, and relative toe lengths are 4 > 3 > 5 > 2 > 1 (Catenazzi and Ttito 2016).

Members of P. chirihampatu are distinguished from most species in this genus by possessing a tubercle-like fold in the inner edge of the tarsus. Within the Psychrophrynella genus, only P. bagrecito and P. usurpator, exhibit this characteristic. These two species are also geographically the closest species to P. chirihampatu. However, P. bagrecito has a sickle-shaped tubercle-like fold along with different ventral coloration that distinguishes it from P. chirihampatu. Psychrophrynella chirihampatu is morphologically most similar to P. usurpator but exhibit a few differences. Whereas P. chirihampatu has a yellow coloration in the ventral region of the body with brown spots, P. usurpator has brown or tan coloration on the ventral region of the body with tan spots. Furthermore, finger 1 is shorter than finger 2 in P. chirihampatu, but about the same length in P. usurpator, the maximum snout-vent length in P. chirihampatu is 27.5 mm whereas the maximum snout-vent length in P. usurpator is 30.5 mm, and P. chirihampatu has a slimmer head compared to P. usurpator, which has a wider, shorter head. Lastly, P. chirihampatu can be differentiated from both P. bagrecito and P. usurpator by its advertisement call, with the former having a single note call (see "Life History" section) while the two latter have multiple note calls (Catenazzi and Ttito 2016).

In preservative, the dorsal region of the body has a gray-tan coloration with a dark brown X marking on the middorsum. There is a dark and narrow interorbital bar that has a cream stripe border on the anterior edge. There is also a dark brown subocular spot and a dark brown stripe leading from the tip of the snout to the top of the insertion of the forelimb both of which are bordered by a narrow cream white lines. From the forelimb to the hindlimb, there is a broken dark dorsolateral line that delineates the dorsum and the flank. The dorsal surfaces of the hindlimbs have dark transverse bars. The anterior portion of the throat is brown and becomes pale gray with brown flecks as it extends posteriorly down the chest and belly where it then becomes yellow on the most posterior end of the ventrum and on the ventral surfaces of the limbs. The posterior side of the thighs are brown and have a pale strip connecting the inside of the knee to the cloaca. The palms and plantars are brown and the fingers and toes are cream. The iris is gray. In life, the coloration is very similar to the color in preservative. The differences are that the dorsal coloration can range from beige to grayish-tan to dark brown with red flecks, the cream lines on the head are bronze in life, the throat is reddish-brown with yellow or orange flecks, the chest and belly range from yellow with reddish-brown, brown, grey with yellow flecks, the ventral surfaces of the limbs may be yellow or orange with reddish-brown, brown, or gray flecks, and the fingers and toes are reddish-brown at the base and yellow at tips (Catenazzi and Ttito 2016).

Dorsal coloration varies from beige to grayish-tan and dark brown. The X mark is less noticeable in darker individuals and individuals may have additional dark dorsal markings. Ventral coloration also varies from yellow to orange and flecks on the ventral surfaces can be reddish-brown, brown, or grey. There is variation in the quality of the dorsolateral line between the limbs ranging from continuous to broken to completely missing. Some individuals have a yellow or orange mid-dorsal line that extends from the snout to the cloaca and then makes its way to the surface of the posterior thigh. Some individuals also have a yellow or orange mid-ventral line that extends from the snout to the cloaca (Catenazzi and Ttito 2016).

The genus Psychrophrynella is distributed among the southern Peruvian Andes and Bolivia. Psychrophrynella chirihampatu are found in the Japumayo valley, region of Cusco, southern Peruvian Andes and inhabit grassland to montane forest habitats at elevations of 2650 to 3180 m. Individuals can be found along the edge of disrupted montane vegetation, such as trails and landslides (Catenazzi and Ttito 2016).

Life History, Abundance, Activity, and Special BehaviorsThe specimens were found during the day in mid to late June under rocks, where males were calling, in disturbed montane forest. Sites of discovery included the sides of trails, natural landslides, and a Playa campsite. Males were also heard calling in other disturbed areas and open space (Catenazzi and Ttito 2016).

The holotype’s advertisement call was recorded at mid-day at an air temperature of 11.6oC on the day of his capture. During a sequence of 26 calls with 9.43 calls/minute the call structure varied such that call notes increased from 57 to 68 in the first 10 calls then declined to 10 notes/call by the 26th. Calls had 10 – 68 single-pulse notes, a rate of 8.7 – 16.55 notes/second, and a duration range of 1.140 – 4.524 ms. The peak frequency range was 2,584 – 2,885 Hz and increased over the call with the first three notes averaging 2,702 ± 38 Hz and the last three notes averaging 2,748 ± 50 Hz. Amplitude and note duration also increased over the course of the call with amplitude increasing by 400% by the last three notes and note duration going from 2.6 ± 0.7 ms during the first three notes to 7.8 ± 1.3 ms during the last three notes (Catenazzi and Ttito 2016).

An unattended nest with 11 eggs was found under a rock at the type locality during initial surveys of this species. The eggs averaged 4.5 mm in diameter. Ten gravid females were also found with varying maturity of their eggs in their ovaries. Females had a range of 7 - 12 eggs and one female had mature eggs that ranged in diameter from 3.5 – 4.6 mm. The species has direct development (Catenazzi and Ttito 2016).

Trends and ThreatsThreats such as over exploitation, invasive species, climate change, habitat destruction, and disease (primarily chytridiomycosis infections from the fungal pathogen Batrachochytrium dendrobatidis, Bd) have all been associated with the collapse of amphibian diversity in the Southern Peruvian Andes (Catenazzi et al. 2011, 2016). However, very little information is known about the conservation statue of P. chirihampatu. Currently, there is no data suggesting any threat to these populations, and preliminary Bd surveys did not detect the presence of Bd in the Japumayo valley. Additionally, the known distribution of their range is on protected land and the species appears to be well suited to the current land use regimen (Catenazzi and Ttito 2016).

CommentsThe species authority is: Catenazzi, A. and A. Ttito. 2016. A new species of Psychrophrynella (Amphibia, Anura, Craugastoridae) from the humid montane forests of Cusco, eastern slopes of the Peruvian Andes. PeerJ 4:e1807 doi.org/10.7717/peerj.1807

Based on genetic distances (uncorrected p-distances) from 16S rRNA mitochondrial sequence data and overall morphology, P. chirihampatu was assigned to the genus Psychrophrynella. Psychrophrynella chirihampatu’s currently known closest relative is P. usurpator, followed by P. guillei and P. wettsteini (Catenazzi and Ttito 2016).

The name "chirihampatu" is derived from the Quechua words "hampa’tu", meaning "toad", and "chiri", meaning "cold" to indicate that the species is a toad living in cold waters. It is, additionally, a wordplay on the genus name, which also means the same thing in Greek (Catenazzi and Ttito 2016).